/*
    Carracci Systems - Carracci Server (openbam project)
    Copyright (C) 2007  Carracci Systems

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

package org.openbam.core.expr;

import org.openbam.core.Event;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

/**
 * A time based window that assumes that all events are in order wrt {@link Event#getEventTime()}.
 * <p>If you expect to receive out of order events,
 *
 * @author inder.sabharwal
 */
public class TimeWindow implements IOperatingWindow {

    protected ArrayList<EvaluatedValue> window = new ArrayList<EvaluatedValue>();
    protected long windowSizeMs = 30000; //30 seconds.

    public TimeWindow(long windowSizeMs) {
        this.windowSizeMs = windowSizeMs;
    }

    public List<EvaluatedValue> getCurrentWindow() {
        return window;
    }

    public void resizeWindow(Event newEvent, IOnResizeHandler resizeHandler) {
        long now = newEvent.getEventTime().getTime();

        Iterator<EvaluatedValue> it = window.iterator();

        //remove all old values from the operating window, and
        //tell the resizeHandler we have done so.
        while (it.hasNext()) {
            EvaluatedValue value = it.next();
            if (now - value.eventTime >= windowSizeMs) {
                it.remove();
                resizeHandler.removed(value);
            } else {
                break;
            }
        }
    }
}
